Evaluating Expressions - intro to formuals

Evaluating Expressions

​review of order of operations. Intro to evaluating algebraic expressions

Multiple Choice

Evaluate the expression:

$$6^2-4\div2$$  

• 4

• 34

• 16

• 10

Here is the order of operations

What does left to right mean on M/D and A/S?

Let's dive in and start evaluating some expressions!

The next several slides are numeric expressions. Remember: to evaluate a numeric expression you use the order of operations to simplify it to a single value.

Multiple Choice

Evaluate the expression.

$$6\cdot2^2+3$$  

• 42

• 27

• 67

• 142

Multiple Choice

Evaluate the expression.

$$\left(8-5\right)\cdot12+3^2$$  

• 54

• 42

• 63

• 45

Multiple Choice

Which student correctly used the order of operations while solving this problem?

Let's take a look at algebraic expressions now!

The next slides are algebraic expressions. Remember: to evaluate an algebraic expression, start by substituting in the value of the variable. Then follow the order of operations to simplify to a single number. video tutorial: https://www.youtube.com/watch?v=kS4H-DOIhAE

Fill in the Blank

Evaluate $$a+6+a$$  when a = 7.

Fill in the Blank

Evaluate $$b^2+4$$ when b = 3. 

Fill in the Blank

Evaluate $$2\left(a-5\right)+2$$ when a = 15 

Fill in the Blank

Evaluate $$-2x$$ when x = -5

Some algebraic expressions have more than one variable!

Just substitute in both variable values at the beginning of the problem.

-4a - 2b

​

​Evaluate when a = -3 and b = 8

Remember to use parenthesis when substituting
-2x + 5
-2(-1) + 5
2 + 5 = 7

evaluate when x = -1

examples to practice together

Multiple Choice

Evaluate $$a-5-b$$ when a = -4 and b = 10. 

• 1

• -9

• -19

• 9

Multiple Choice

Evaluate $$\frac{16+2x}{y+1}$$ when x = -2 and y = -4 

• -4

• 5

• 2

• -6

Multiple Choice

if the perimeter of a rectangle is 2l + 2w

find the perimeter of of a rectangle with length of 4 in and a width of 8 in

• 24 in

• 16 in

• 12

• -3

Open Ended

If you were to be given a test on evaluating expressions right now, what do you think your score be? Why?